The investigators plan to measure changes in muscle protein metabolism in response to feeding, comparing between a single large essential amino acid (EAA) feed (the normal building blocks of protein) and the provision of the same dose in 4 smaller feeds at 45min intervals. The investigators will perform this study in healthy older (65-75y) and younger (18-28) men. The investigators will also explore how feeding affects muscle blood flow as this is important in the delivery of the nutrients we eat to the muscle where they are used.